1. Surface engineering of hematite nanorods photoanode towards optimized photoelectrochemical water splitting.
- Author
-
Li, Zhenzi, Wu, Jiaxing, Liao, Lijun, He, Xiangyi, Huang, Baoxia, Zhang, Shiyu, Wei, Yuxiu, Wang, Shijie, and Zhou, Wei
- Subjects
- *
HEMATITE , *PHOTOCATHODES , *FERRIC oxide , *SEMICONDUCTOR defects , *CHARGE transfer , *NANORODS , *CHARGE carriers , *METALLIC oxides - Abstract
One-dimensional (1D) defective γ-Fe 2 O 3 nanorods (DFNRs) photoanode is fabricated via solvothermal and high-temperature hydrogenation strategies, which exhibits excellent visible-light photoelectrochemical performance and long-term stability, due to the formation of moderate oxygen vacancy defects promoting spatial charge separation and transfer at semiconductor/electrolyte interface, and 1D nanorod structure favoring rapid charge transfer. [Display omitted] • γ-Fe 2 O 3 nanorods photoanode with engineered surface oxygen vacancy are fabricated. • It exhibits excellent visible-light photoelectrochemical performance and long-term stability. • It can be ascribed to the formation of moderate oxygen vacancy defects promoting spatial charge separation and transfer at the semiconductor/electrolyte interface. • 1D nanorod structure is favoring rapid charge transfer. • The surface of γ-Fe 2 O 3 with amounts of hydroxyl (–OH) provides adequate surface-active sites. Rapid charge recombination in hematite (Fe 2 O 3) during photoelectrochemical water splitting is a major obstacle to achieving high-efficiency photoelectrodes. Surface defect engineering is considered as a viable strategy for enhancing photoelectrochemical activity of oxide photoanodes. Herein, a one-dimensional (1D) defective γ-Fe 2 O 3 nanorods (DFNRs) photoanode is prepared using solvothermal and high-temperature hydrogenation strategies. The as-prepared DFNRs possess superior visible-light absorption capacity and exhibit excellent photoelectrochemical performance (0.98 mA cm−2), with approximately three-fold higher photocurrent density than that of pristine Fe 2 O 3 (FNRs, 0.32 mA cm−2). The enhanced activity of the DFNRs results from the moderate formation of oxygen vacancy defects, which promotes spatial charge separation and transfer at the DFNRs/electrolyte interface, as well as the 1D nanorod structure, which favors rapid charge transfer. The surface of γ-Fe 2 O 3 with hydroxyl (OH) groups provides sufficient surface-active sites. This result suggests that surface-oxygen deficiency of γ-Fe 2 O 3 can not only expand the light absorption range but also facilitating photo-generated charge carriers separation. This surface engineering strategy provides an alternative method for preparing stable and highly active metal oxide photoanodes for photoelectrochemical water splitting. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF